These types of casings are used in conjunction with almost any turbo-machine irrespective of whether the turbo-machine is axially traversed or radially traversed. Said designs are additionally conceivable for turbo-machines with a horizontally divided casing or for barrel-type turbo-machines or for turbo-machines with a vertical parting line. Both in the case of expanding turbo-machines and in the case of compressing turbo-machines, the pressures and temperatures of the process fluid are decisively important to the design and the dimensioning, in particular of the casing. The places which enable access to the interior of the casing, that is, for example, parting lines or opening possibilities which are closable in a different manner, for example end-faces covers, form a natural weak point of the casing. A further weak point of the casing and of the overall structure is frequently provided as a result of passages of the rotor through the casing, which have to be sealed by means of a shaft seal. Shaft seals are frequently regions which have a radial clearance which is to be reduced where possible in relation to the shaft so that an anticipated leakage of the process fluid is small. However, the radial clearances cannot be reduced arbitrarily as the thermal load of the casing and of the remaining machine components, in particular in the case of non-stationary operation, is not the same for all machine components and consequently thermal relative expansion occurs—also caused by different materials—which can result in a clearance reduction. In addition, radial clearance requirements from the rotor dynamics and necessary production tolerances have to be taken into account. Only when the sum of the radial clearance requirements plus a safety margin are reflected in the design is the operational safety of the machine actually guaranteed.
DE3100039A1 makes known an alignment of a cover in a circumferential direction of a longitudinal axis.
U.S. Pat. No. 4,822,240 shows a barrel casing, the cover of which carries a bearing and a seal.
FR 593 316 A and GB 1010300 A disclose in each case the bearing arrangement for an internal casing in an external casing.